Mechanical resonance is the tendency of a mechanical system to absorb energy when the frequency of its oscillations matches the system's natural frequency of vibration in higher level than it absorbs energy at other frequencies. Mechanical resonance may cause violent swaying motions and even catastrophic failure in improperly constructed structures including aircrafts. Other forms of dynamic instabilities—such as flutter—may also insert various forms of vibration into various parts of the aircraft.
When designing aircrafts, it is customary for engineers to implement various means to ensure that mechanical resonance frequencies of the component parts of the aircraft do not match driving vibrational frequencies of motors or other oscillating parts on the aircraft. Such means may include, for example, different kinds of shock absorbers and other absorbers, as well as other means of dissipating the absorbed energy.
Furthermore, vibrations usually reduce the effectivity of various systems which are installed on the aircraft (e.g. sensors, mounts, mechanical components and so on). Therefore, extra means are usually used in order to prevent vibration of systems installed in the aircraft with respect to the body of the aircraft (including the chassis as well as the external structural surfaces).
U.S. Pat. No. 8,517,313 by Amihay Gornik, entitled “Mechanical Vibration Deicing System” discloses an aircraft deicing system including at least one motor operative to drive at least one eccentric mass in rotational motion and at least one displacer coupled to at least one location on at least one aircraft surface and coupled to the at least one eccentric mass such that forces produced by the rotational motion of the eccentric mass are applied to the at least one displacer, causing the at least one displacer to displace the at least one aircraft surface in a plurality of directions at each of the at least one location, thereby causing disengagement of ice from the at least one aircraft surface.